Estimation of aging period of Ezo-shika deer (<i>Cervus nippon yesoenis</i>) meat required for tenderization

<p>To clarify the aging period of meat of Ezo-shika deer (Cervus nippon yesoenis) required for tenderization, we collected semitendinosus muscles from three wild deer immediately after they were hunted and killed. The muscles were stored at 4℃ for 21 days postmortem. Measurements of pH and shear force, determination of myofibrillar fragmentation index (MFI), SDS-PAGE analysis of myofibrillar proteins, and western blotting using anti-troponin-T and antidesmin antibodies were performed. At 12 h postmortem, the pH of the semitendinosus muscle reached a minimum value of 5.65. Shear force was 1.45 kg/cm² at day 1 postmortem. The semitendinosus muscle tended to be tenderized at day 5 postmortem, with shear values reaching 0.82 kg/cm². The degree of MFI in the semitendinosus muscle increased to 0.63 at day 10 postmortem. SDS-PAGE revealed the absence of α-connectin (titin-1) at day 10 postmortem. As well, a 30 kDa band was obviously evident at day 7 postmortem. Western blotting using anti-troponin antibody showed that the band resulted from troponin degradation. The density of the 30 kDa band was greatest at day 10 postmortem. The density of the desmin band decreased during the postmortem period and a 38 kDa fragment resulting from desmin degradation was clearly evident at day 10 postmortem. Based on these results, we conclude that Ezo-shika deer meat requires 7 to 10 days aging postmortem for tenderization.</p>